Synthesis, crystal structure and thermal analysis of tetraiodo-4,4′-bi-1,2,4-triazole

Tetraiodo-4,4'-bi-1,2,4-triazole (1) was synthesized from a reaction of iodine monochloride with 4,4'-bi-1,2,4-triazole (2), which was prepared by a transamination reaction between 4-amine-1,2,4-triazole and N,N-dimethylformamide azine dihydrochloride (3) obtained via a Vilsmeier reaction. The title compound was extensively characterized by melting point, elemental analysis, IR, HRMS and single crystal X-ray diffraction. The single crystal X-ray structural analysis reveals that compound I exhibits a stable conformation with the two triazole rings being perpendicular to minimize three-dimensional steric hindrance and stacking through aromatic pi...pi packing interactions between molecules. The thermal analysis from TGA and DSC indicates that compound 1 decomposes at 275.40 degrees C and 338.35 degrees C, respectively. (C) 2013 Hong-Bo Li. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.